Low-Cost Visual Tracking of a Landing Place and Hovering Flight Control with a Microcontroller

Abstract

The growth of civil and military use has recently promoted the development of unmanned miniature aerial vehicles dedicated to surveillance tasks. These flying vehicles are often capable of carrying only a few dozen gramms of payload. To achieve autonomy for this kind of aircraft novel sensors are required, which need to cope with strictly limited onboard processing power. One of the key aspects in autonomous behaviour is target tracking. Our visual tracking approach differs from other methods by not using expensive cameras but a Wii remote camera, i.e. commodity consumer hardware. The system works without stationary sensors and all processing is done with an onboard microcontroller. The only assumptions are a good roll and pitch attitude estimation, provided by an inertial measurement unit and a stationary pattern of four infrared spots on the target or the landing spot. This paper details experiments for hovering above a landing place, but tracking a slowly moving target is also possible.

An Onboard Monocular Vision System for Autonomous Takeoff, Hovering and Landing of a Micro Aerial Vehicle

“…Lange et al [14] achieved autonomous landing and position control of a MAV by estimating the 3D position from a landing pad consisting of several concentric circles, assuming that the UAV is flying exactly parallel to the landing pad and the ground plane. Wenzel et al [22] presented a low-cost solution for visual tracking a landing place by using a Wii remote infrared camera and four infrared LED markers. In [23], they achieved takeoff, hovering and landing of a MAV on a moving platform.…”

Automatic Take Off, Tracking and Landing of a Miniature UAV on a Moving Carrier Vehicle

“…Our previous Wii remote related projects [22] and [21] required an inertial measurement unit with accurate roll and pitch estimates to work properly and did not consider a moving start and landing platform. The current system is able to calculate the current position only by interpreting geometric information.…”

Automatic Take Off, Hovering and Landing Control for Miniature Helicopters with Low-Cost Onboard Hardware

“…By combining the geometric and the physical roll and pitch angles, the real x and y values can be calculated with respect to the current z value. This is described in detail in [11].…”

“…We demonstrated in [11] how a infrared camera can be used as main sensor for stable quasi-stationary flight control. In this paper we show how the same system can be used for autonomous take off, hovering and landing.…”